Apparatus for precluding certain settings in a permutation switch



March 16, 1965 T. B. SANDS APPARATUS FOR PRECLUDING CERTAIN SETTINGS IN A PERMUTATION SWITCH Filed Jan. 17, 1963 2 Sheets-Sheet 1 INVENTOR TIMOTHYB. 841m:

March 16, 1965 -r B SANDS 3,174,001

APPARATUS FOR PECLUDING CERTAIN SETTINGS IN A PERMUTATION SWITCH Filed Jan. 17, 1965 2 Sheets-Sheet 2 INVENTOR. TIMOTHY 3 5mm:

United States Patent 3,174,001 APPARATUS FOR PRECLUDING CERTAIN SETTINGS: IN A PERMUTATION SWITCH Timothy B. Sands, St. Paul, Minn, assignor to Honeywell Inc, a corporation of Delaware Filed Jan. 17, 1963, Ser. No. 252,136 6 Claims. {CL 200-14) This invention relates to position selecting apparatus and more particularly to position selecting apparatus of the permutation type wherein two or more rotatable selector members are operably interconnected by lost motion means so that the members may be positioned as desired by manipulation of a single manually rotated control member which is connected to one of the selector members. Specifically, the invention is directed to an improved permutation device including means for precluding certain unsafe or otherwise undesirable combinations of settings of the selector members therein.

Permutation type position selecting apparatus per se is well known and has found application in many areas. These include the well known combination locks and switches as Well as various other devices wherein it is desired to mechanically position a plurality of selector members by the manipulation of a single control member. One of the advantages of this type of arrangement is that an otherwise relatively bulky mechanism can be constructed in a very compact unit.

In some recent applications where permutation type position selecting apparatus has been used in connection with switching and other positioning functions, it has been found that certain combinations of settings of the selector members result in a condition which is either unsafe or otherwise undesirable in these applications. In the present invention I have provided structure which precludes setting of these unsafe or otherwise undesirable combinations of settings of the selector members in per mutation type position selecting apparatus.

Therefore an object of my invention is to provide improved position selecting apparatus of the permutation type.

A further object of my invention is to provide, in a permutation type position selecting device having two or more rotatable selector members, means to preclude certain unsafe or otherwise undesirable combinations of settings of the members.

Still another object of my invention is to provide position selecting apparatus of the type described above which is relatively simple in construction and extremely compact.

These and other objects of the invention will become apparent upon reading the following detailed description of a preferred embodiment of the invention in conjunction with the accompanying drawing wherein:

FIGURE 1 is a top view, with portions broken away, of a permutation switch which utilizes the present invention.

FIGURE 2 is a longitudinal cross sectional view of the permutation switch taken generally along line 2-2 of FIGURE 1.

FIGURE 3 is a cross sectional view of the device taken generally along line 3-3 of FIGURE 2.

FIGURE 4 is a perspective view of an operating shaft for the device.

FIGURE 5 is a bottom view of a first selector member which forms a part of the invention.

FIGURE 6 is a fragmentary cross sectional view taken generally along 6-6 of FIGURE 5.

FIGURE 7 is a top view of a motion transmitting member which forms a part of the present invention.

3,l?4,%l Patented Mar. 16, 1965 FIGURE 8 is a top view of a second selector member which also forms a part of the invention.

FIGURE 9 is a fragmentary cross sectional view taken generally along 9-9 of FEGURE 8.

FIGURE 10 is a cross sectional View taken generally along line Ill-Iii of FIGURE 8.

Referring to the drawing, the reference numeral 10 generally designates a permutation switch which utilizes the present invention. As seen in FIGURES l and 2, the device includes a body which is made up of a base member 11, a central member 12 fixed thereto and hereinafter referred to as the fixed member, an upper body member 13 and a cover 14. Members 11, 12 and 13 are formed of an electrically insulative material such as plastic. Base member 11 is a generally cup-shaped memher having a bottom 15 and upwardly extending walls 16. Extending upward from bottom 15 is a centrally located hub portion 17 having a circular recess 26 formed therein. At the upper surface of wall 16 are formed ten equally spaced shallow notches in which are mounted electrical contacts Zliwhich may be held in place by appropriate means such as rivets 22 extending vertically through wall 16 of base member 11.

Fixed member 12, which is mounted directly above base 11 and which is fixed thereto by means that will be discussed hereinafter, is of a generally circular shape and has upwardly and downwardly extending annular shoulders 24 and 25 respectively at the periphery thereof. At its center, fixed member 12 has an aperture 26 formed therethrough of a diameter substantially equal to that of recess 20 in base 11. As best seen in FIGURE 3, fixed member 12 also has formed in its upper surface annular groove 27 which includes a main portion 30 and a rela tively short portion 31 having a reduced radius with respect to the main portion.

Mounted directly above fixed member 12 is upper member 13 which has, at its periphery, an annular downwardly extending wall 32 and an outwardly extending flange 33. Intermediate wall 32 and flange 33 is an inwardly extending annular flange 34. The lower surface of wall 32 has formed therein 1() equally spaced notches similar to those formed in wall 16 of base member 11 and in these notches are mounted electrical contact members 35 which are similar to electrical contacts 21. Contacts 35 may be held in place by appropriate means such as rivets 36 extending vertically through Wall 32. Body members 11, 12 and 13, as stated previously, are rigidly fixed together. This may be accomplished by appropriate means such as screws 27, the heads of which can be seen in FIGURE 1, extending vertically through the members and spaced intermediate rivets 22 and 36.

Cover 14 is also of a generally circular shape having an outside diameter substantially equal to the diameter of flange 33 of upper body member 13. Cover 14 is attached to the rest of the body by appropriate means such as screws 40 extending through cover 14 and into flange 33. At its center, cover 14 has a hub portion 41 of increased thickness which has formed therein an aperture 42. Cover 14 also has formed, substantially intermediate its central hub portion 41 and the outer periphery of the cover member, a small rectangular opening 43 the purpose for which will become apparent hereinafter.

Extending through the device is an operating shaft 44 which is better shown in FIGURE 4. Shaft 44 has a main portion 45 having a diameter substantially equal to the diameter of recess 26 and aperture 26 hereinbefore described and having a pair of fiattcd sides 45a. At the upper end of shaft 44 is a reduced diameter portion 46 having a diameter corresponding to the diameter of aperture 42 in cover 14. Mounted on reduced diameter portion 46 of shaft 44, above cover 14, is a manual control knob 47 which is attached to the shaft by appropriate means such as a screw 50. Shaft 44 is thus rotatably mounted within the body of device 10 and is held in place by cover 14.

Mounted within the body of permutation switch lltl and slightly below cover 14 is a first selector member 51. A portion of the top of first selector member 51 can be seen in FIGURE 1 and a bottom view of the member is shown in FIGURE 5. First selector member 51 is mounted on shaft 44 and has an aperture 52 therethrough corresponding to flatted main portion 45 of the shaft, and hence first selector member 51 is mounted for rotation with the shaft. First selector member 51 is of a generally circular shape having a radial abutment member 53 extending from a portion of the periphery thereof. First selector member 51 also has a downwardly extending concentric hub portion 54; and extending downwardly from radial abutment member is a. second abutment member 55 which extends downward to substantially the same distance as does hub 54. As seen in FIGURE 5, second abutment member 55 is actually an annular segment having an inner radius substantially equal to the radius of first selector member 51 and an outer radius somewhat shorter than the radius of radial abutment member 53. The details of second abutment member 55 can be better understood by referring to the fragmentary cross sectional view shown in FIGURE 6.

Mounted around the periphery of hub portion 54- of first selector member 51 is an annular motion transmitting member 56, a plan View of which is shown in FIG- URE 7. Motion transmitting member 56 has an inner radius substantially equal to the radius of hub member 54 and an outer radius substantially equal to the radius of first selector member 51. Motion transmitting member 56, when mounted on downwardly extending hub 54 of first selector member 51, is rotatable with respect thereto. Motion transmitting member 56 includes a relatively narrow protrusion 57 extending radially from the outer periphery thereof. Protrusion 57 extends outwardly from the periphery of motion transmitting member 56 to a distance from the center that is substantially equal to the radius of radial abutment member 53 of first selector member 51.

Rotatably mounted directly below first selector member 51 and axially retained between fixed member 12 and inwardly extending flange 34 of upper body member 13, is a second selector member 6%. Second selector member 69 is formed of an electrically insulative material and has a main portion 61 which provides an upper surface which slidably engages the lower surface of hub 54 of first selector member 51. At the outer periphery of main portion 61, second selector member 60 has formed upwardly and downwardly extending walls 63 and 64 respectively. At its center, main portion 61 has a downwardly extending hub portion 65. Centrally located in second selector member 60 is a circular aperture 66 of substantially equal diameter to that of main portion 45 of shaft 44. Thus second selector member 68 is rotatable with respect to the shaft. As seen in FIGURE 2, second selector member 60 has a diameter somewhat greater than the diameter of first selector member 51.

As best seen in FIGURE 8, which is a top view of second selector member 60, and in FIGURES 9 and 10, which are cross sectional views thereof, second selector member 60 has formed on the upper side of main portion 61 and co-extensive with upwardly extending Wall 63, an inwardly extending barrier member 67. Barrier member 67 is actually an annular segmental member having an inner radius substantially equal to the outer radius of second abutment member 55 of first selector member 51. At each of its ends, barrier member 67 has concave surfaces 68 which are adaptedtb be abutted by the rounded end of protrusion 57 on motion transmitting member 56. It will be noted that the inner radius of Wall 63 is substantially equal to or slightly greater than the distance protrusion 57 extends from the center. Barrier member 67 extends axialy upward from main portion 61 of second selector member 6%) to a distance such that it can be engaged by protrusion 57 but is terminated so that it does not interfere with radial abutment member 53 of first selector member 51.

As seen best in FIGURES 8 and 9, second selector member 6%, has formed therethrough a radially extending slot 76 which substantially bi-sects barrier member 67 and extends through upwardly extending wall 63.

Mounted on the underside of main portion 61 of second selector member 60 is a pivoted further abutment member generally designated by the numeral 71. Pivoted further abutment member 71 includes an arm 72 which has its outer end extending into a cut away portion (FIGURE 3) of downwardly extending Wall 64 of second selector member 60. At this outer end of arm 72 is a pivot pin 73 extending axially in wall 64. At the inner end of arm 72 is a pin 74 attached at a point somewhat below its center to arm 72. The upwardly extending end of pin 74 extends through slot 70 and upward to a point slightly below the upper surface of wall 63 of second selector member 60. The lower end of pin 74 extends downward to a point somewhat below the lower end of wall 64 of second selector member 60. As best seen in FIGURES 2 and 3, the lower end of pin 74 is adapted to slidably ride in annular groove 27 in fixed member 12 and act as a guide for radial movement of the upper end. As second selector member 6b is rotated with respect to fixed member 12, pin 74, which is connected to second selector member 66, is normally retained in a first or outer position in slot 70 which corresponds to main portion 30 of annular groove 27. When second selector member 60 is moved to a position so that pin 74 is in reduced radius section 31 of groove 27, the pin will be moved in slot 70 to a second or inward position as shown in FIGURES 2, 3, and 4. As will be seen hereinafter, the first position of pin 74 described above is at a radial distance from the axis of rotation of the selector members such that the pin is located in a position of greater radius than the radius of radial abutment member 53 of first selector member 51. However, when pin 74 is in its second or inner position, it is in a position to abut the edges of radial abutment member 53 on first selector member 51.

As seen in FIGURES 2 and 3, downwardly extending hub portion 65 of second selector member 63 has formed at its lower end a detent wheel 75 which has, in its preferred embodiment, ten detents equally spaced about its periphery. Mounted on the upper surface of fixed member 12 are a pair of pivoted arm members 76 and 77 each having a roller 8&3 which is adapted to ride along the surface of the detent wheel 75. Pivoted arm members 76 and 77 are spring biased into engagement with detent Wheel 75 by appropriate means such as springs 81 and 82. Thus, through the co-action of detent wheel 75 and pivoted arm members '76 and 77, ten equally spaced angular positions of second selector member 60 are defined.

Located intermediate base member ill and fixed member 12 is a member 83 which is rotatable with shaft 44 as is first selector member 51. Member 33 is formed of electrically insulative material and has formed at its upper surface a detent wheel 84 which is substantially identical to detent wheel 75 previously described. A pair of pivoted arms 85 and 86 co-act with detent wheel 84 in a manner exactly similar to that described in connection with detent wheel 75 and pivoted arm members 76 and 77. Since both first selector member 51 and member 33 are connected to shaft 44, the co-action of detent wheel 84 and spring biased, nivoted arms 85 and 86 defines ten equally spaced angular positions of first selector member 51.

Imbedded in downwardly extending Wall 64 of second selector member 60 and extending slightly outward from the outer periphery thereof is a conductive ring 87 having an outwardly extending contact portion 90 which is adapted to co-act with contacts 35 previously described herein. Similarly, member 33 has imbedded therein an annular conductive ring 9 which has a radially extending contact portion 92 which co-acts with fixed contacts 21. While not shown it is to be understood that conductive rings 87 and 91 may be connected into an electrical circuit by means of an electrical contact coacting with the annular extending portions of the rings. Thus an electrical circuit may be established through the conductive rings and through any one of the ten fixed contact members depending on the position of the selector members. It will thus be seen that two electrical circuits may be selectively established by the rotation of the two selector members 51 and tit) and the contacts 963' and 92 which are movable therewith.

As seen in FIGURE 1, first selector member 51 has on its upper surface the numerals through .9 corresponding to the ten positions defined by detent wheel 84. An annular ring 93 which is attached to the upper end of wall 63 of second selector member 60 has the numerals 0 through 9 thereon corresponding to the ten positions of second. selector member 60 which are defined by detent wheel '75. These numerals are visible through rectangular opening or window 43 previously described herein. By rotation of selector members 51 and 60 various combinations of settings of the two members may be obtained.

Having described the structure of the device, a description of its operation will now be given.

As previously noted, this switch is designed to provide for selectively connecting together a large number of alternate electrical circuits by rotating a pair of concentrically mounted selector members to a plurality of unique positions with respect to each other. In each of the unique positions, means are provided to establish the required circuit.

As disclosed in FIGURE 1, the physical act of setting the switch is accomplished by turning knob 47 in either direction. Knob 47 is connected directly to first selector member 51, which in turn is connected by intermediate lost motion members to annular ring 93. Knob 47 is turned in one direction until the lost motion members make contact to cause movement of ring 3 in the same direction. The desired number from 0 to 9 on ring 93 is then positioned in window 43. The rotation of knob 43 is then stopped and reversed until the proper number from .0 to .9 on first selector member 51 appears in window 43. The selector members are then in position to make the desired electrical circuit or circuits.

In some applications it is unsafe or otherwise undesirable to allow certain settings to appear in window 43. The purpose of this invention is to provide means to preclude the setting of certain number combinations in window 43, while allowing all other combinations to be set without interference. In the preferred embodiment disclosed herein, the number combinations 0.0, 0.1 and 0.2 are considered undesirable, and the switch is constructed so as to preclude such settings. If ring 93 is set at any number from 1 through 9, then first selector member 51 can be set to any number from .0 to .9. However, if ring 93 is set to 0, then first selector member 51 cannot be set to .0, .l or .2. The mechanism for accomplishing this function will be explained in the following paragraphs.

T o understand the operation of the setting mechanism and the mechanism for precluding undesirable number combinations, only four moving parts need be considered. These are first selector member 51 (FIGURE 5), motion transmitting member 56 (FIGURE 7), second selector member d0 (FIGURE 8) and pivoted further abutment member 71 (FIGURES 3 and 10).

As disclosed in FIGURE 2, motion transmitting member 56 (FIGURE 7) is rotatably mounted on hub 54 of first selector member 51 (FIGURE 5). These two members can be rotated with respect to each other less than one full revolution since protrusion 57 will come in contact with second abutment member when the two members are rotated with respect to each other in either direction. Since knob 47 is connected directly to first selector member 51 by shaft 44, rotation of knob 47 will initiate rotation of motion transmitting member 56 within one full revolution of knob 47.

The function of motion transmitting member 56 is to provide the lost motion connection between first selector member 51 and second selector member (ring 93). FIGURES 3 and 8 disclose that shaft 44 is free to rotate within circular aperture 66 without affecting the position of second selector member 60. In order to position second selector member 60 (and ring 93 connected thereto), the rotation of first selector member 51 must be utilized.

Since numeral carrying ring 93 is connected directly to second selector member 60, any movement of member at} will result in the positioning of the numerals on ring 93 within window 43. As disclosed in FIGURE 2, motion transmitting member 56 is placed around hub 54 of first selector member 51, and then these two members are turned over from the position disclosed in FIGURE 5 and placed on top of second selector member 60 disclosed in FIGURE 8. The flat surface of hub 54 (FIGURE 5) and the surface of motion transmitting member 56 are then disposed against the upper flat surface of second selector member on (FIGURE 8). The rounded tip of protrusion 57 is then in position to abut concave surfaces 68 of barrier member 67 since the distance of the tip of protrusion 57 from the center is substantially equal to the inner radius of upstanding wall 63 of second selector member 60.

As knob a7 is rotated, first selector member 51 rotates with it. Within one revolution, second abutment member 55 contacts protrusion 57 to initiate rotation of motion transmitting member 56. Protrusion 57 on motion transmitting member 56 then contacts barrier member 6'7 within one more revolution to initiate rotation of second selector member 60 (ring 93). When ring 93 is in the desired position, the direction of rotation of knob 47 is reversed. Second selector member 60 (ring 93) and motion transmitting member 56 will remain in position when the direction of rotation is reversed, and first selector member 51 is rotated in the reverse direction less than one full revolution to place the proper number from .0 to .9 in window 43.

The above has been a description of the standard operation of the switch, where the means for precluding undesirable number combinations has not been utilized. The operation of that portion of the switch will now be described.

Referring now to FIGURE 3, there is disclosed a top view of fixed member 12; a sectional view of downwardly extending Wall 64 of second selector member 60; and a sectional view of pivoted member 71. A generally concentric groove 27 has been cut into the top surface of fixed member 122. Groove 27 includes a main portion 30 and a reduced radius portion 31. Arm 72 of pivoted member 71 is connected to second selector member 60 by pivot pin 73. Pivoted member '71 therefore rotates with second selector member 6%) While fixed member 12 remains in a fixed position. Pin '74 is attached to the end of arm 72 opposite pivot pin 73. The lower end of pin 74 rides in groove 27 to guide the movement of pivoted member 71.

It can be seen from FIGURE 3 that as second selector member 60 (wall 64) is rotated with respect to fixed member 12, pin 74 will change its distance from the center as it rides in groove 27. As disclosed in FIGURE 8, this radial movement of pin 74 takes place in a radial slot in second selector member 6t Reduced portion 31 of groove 27 is positioned such that pin '74 will enter reduced portion 31 at the same time as the numeral 0 on ring 93 (connected to second selector member 60) enters window 43. Pin '74 will thus be at its inner position with respect to the center during the time that the numeral appears in window 43.

It is again noted that the purpose of pin '74 is to prevent the setting of the numbers .0, .1 and .2 on first selector member 51 in window 43, during the time that ring 533 is set to 0. Pin 74 in its inner position is thus a signal to first selector member Sl that the possibility of selecting undesirable number combinations is present. In order to utilize the signal, radial abutment member 53 of first selector member 51 extends outwardly from the periphery of member 51 at the positions marked .0, .1 and .2 thereon.

From FIGURES 8 and 9, it can be seen that pin 74 extends above barrier member 67. From FIGURE 1 it can be seen that radial abutment member 53 is positioned high enough on first selector member 51 to clear barrier member 67 during rotation. With pin 74 in the inner position disclosed in FIGURES 3 and 8, however, one edge of radial abutment member 53 will abut pin 74 during rotation of first selector member 51 to prevent the numbers .0, .1 and .2 from being set in window 43.

Once ring 5 3 is moved so that the numeral 0 no longer occupies window 43, the lower end of pin 74 will move to the main portion fill of groove 27 to place pin 74- in its outer position in slot 79 where it is not in position to interfere with the rotation of first selector member 51.

From the foregoing it will be seen that I have provided a relatively simple and compact permutation type position selecting apparatus wherein are provided means for excluding certain unsafe or otherwise undesirable combinations of settings of the selector members therein. It will be obvious that the number of positions of each of these selector members may be varied by merely chang ing the detent Wheels '75 and 84 Also the number of combinations excluded may be varied by changing the angular length or" radial abutment member 53 on first selector member 51 and of portion 31 of annular groove 27 in fixed member 12. Also, while the invention has been shown in connection with switch apparatus, it is to be understood that it may be used equally as well in any application where it is desired to angularly position two or more members.

Therefore, while a single illustrative embodiment of my invention has been shown and described herein, it will be obvious that various modifications and changes will become apparent to those skilled in the art. Therefore it is to be understood that my invention is to be limited only by the scope of the appended claims.

I claim:

1. Position selecting apparatus comprising: a fixed member; first and second selector members mounted on said fixed member for relative rotation with respect to each other and for rotation with respect to said fixed member; means connected intermediate said first and second selector members effective to limit relative rotation therebetween to an amount less than two complete rotations and to connect said selector members for unlimited simultaneous rotation within two relative rotations; and means connected to one of said selector members operable upon movement of said one selector member to a pre-selected position with respect to said fixed member, to engage corresponding means on the other of said selector members to prevent movement of said other selector member to certain of its positions with respect to said one selector member.

2. Position selecting apparatus comprising: a fixed member; first and second selector members, said selector members being mounted on said fixed member for relative rotation with respect to each other and each for rotation through a plurality of predetermined angular positions wtih respect to said fixed member; a lost motion member connected intermediate said selector members; means associated with said lost motion member and said first and second selector members to limit relative angular movement between said first selector member and said i lost motion member to a portion of a complete rotation and to limit relative angular movement between said lost motion member and said second selector member to a portion of a complete rotation; said first selector member and said second selector member thereby being connected for unlimited simultaneous rotation by said lost motion member within two relative rotations of said selector members; and abutment means connected to said second selector member and operable upon movement thereof to certain of its angular positions with respect to said fixed member, to mesh with a corresponding abutment means on said first selector member to preclude movement of said first selector member to certain preselected positions with respect to said second selector member.

3. Position selecting apparatus comprising; a fixed member; first and second selector members, said selector members being mounted on said fixed member for relative rotation with respect to each other and each for rotation through a plurality of predetermined angular positions with respect to said fixed member; a motion transmitting member mounted on said fixed member for relative angular movement with respect to said selector members, said motion transmitting member including a protrusion mounted thereon, radial abutment means and second abutment means mounted on said first selector member, said second abutment means being cooperable with said protrusion to limit relative angular movement between said first selector membber and said motion transmitting member to a portion of a complete rotation; barrier means associated with said second selector member and cooperable with said protrusion to limit relative angular movement between said motion transmitting member and said second selector member to a portion of a complete rotation; and further abutment means mounted on said second selector member and operable upon movement thereof to certain of its angular positions with respect to said fixed member, to cooperate with said radial abutment means to preclude movement of said first selector member to a number less than all of its angular positions with respect to said second selector member.

4. Position selecting apparatus, comprisin a fixed member; first and second generally co-axially mounted selector members, said selector members being mounted on said fixed member for relative rotation with respect to each other and each for rotation through a plurality of predetermined angular positions with respect to said fixed member; a motion transmitting member mounted intermediate said first and second selector members for relative angular movement with respect thereto, said motion transmitting member having a protrusion formed thereon, a radial abutment member and a second abutment member mounted on said first selector member, said second abutment member being cooperable with said protrusion to limit relative angular movement between said first selector member and said motion transmitting member to a portion of a complete rotation; a barrier member mounted on said second selector member and cooperable with said protrusion to limit relative angular movement between said motion transmitting member and said second selector member to a portion of a complete rotation; a further abutment member mounted on said second selector member and movable between first and second poistions with respect thereto, said further abutment member being effective when in said first position to cooperate with said radial abutment member to preclude movement of said first selector member to a number less than all of its angular positions with respect to said second selector member, said second position being a neutral or inoperative position of said further abutment member; and means eitective upon movement of said second selector member through certain of its angular poistions with respect to said fixed member to maintain said further abutment member in said first position and eii'ective upon movement of said second selector member through the remainder of its angular positions to maintain said further abutment member in said second position.

5. Position selecting apparatus comprising: a fixed member; first and second generally co-axially mounted selector members, said selector members being mounted on said fixed member for relative rotation with respect to each other and each for rotation through a plurality of predetermined angular positions with respect to said fixed member; means for manually rotating said first selector member; a motion transmitting member mounted intermediate said first and second selector members for relative angular movement with respect thereto, said motion transmitting member having a protrusion formed thereon, an abutment member mounted on said first selector member, said abutment member extending toward said second selector member and being cooperable with said protrusion to limit relative angular movement between said first selector member and said motion transmitting member to a portion of a complete rotation; a radial abutment member extending substantially radially outward from a portion of the periphery of said first selector member, a barrier member mounted on said second selector member and cooperable with said protrusion to limit relative angular movement between said motion transmitting member and said second selector member to a portion of a complete rotation; a further abutment mem ber mounted on said second selector member and movable in a substantially radial direction between first and second positions with respect thereto, said further abutment member extending from said second selector member toward said first selector. member and being effective when in said first position to cooperate with said radial abutment member to preclude movement of said first selector member to a number less than all of its angular positions with respect to said second selector member, said further abutment member in said second position being at a radial distance from the center of said selector members greater than the radius of said radial abutment member and therefore being inoperative to preclude movement of said first selector member; said fixed member including a surface adjacent said second selector member and in a plane substantially parallel to the plane of rotation of said second selector member, said surface having an annular groove formed therein, said annular groove being substantially co-axial with said selector members and including a main portion and a relatively shorter portion of a reduced radius with respect thereto; and said further abutment member having a pin-like. member attached thereto acting as a guide member for said further abutment member said guide member being slidably seated in said annular groove, said guide member being effective to maintain said further abutment member in said second position when said second selector member is in a position with respect to said fixed member so that said guide member is in said main portion of said groove and to maintain said further abutment member in said first position when said guide member is in said reduced radius portion of said groove.

6. The position selecting apparatus of claim 5 wherein said apparatus further includes first and second pluralities of electrical contact means fixed with respect to said fixed member, and first and second movable contact means cooperable therewith mounted for movement with said first and second selector members respectively.

References Cited by the Examiner UNITED STATES PATENTS 2,565,083 8/51 Morton 200-14 X 2,811,594 10/57 Papouschek 200-14 2,614,181 10/52 Consalvi et a1 200-14 X BERNARD A. GILHEANY, Primary Examiner. 

1. POSITION SELECTING APPARATUS COMPRISING: A FIXED MEMBER; FIRST AND SECOND SELECTOR MEMBERS MOUNTED ON SAID FIXED MEMBER FOR RELATIVE ROTATION WITH RESPECT TO EACH OTHER AND FOR ROTATION WITH RESPECT TO SAID FIXED MEMBER; MEANS CONNECTED INTERMEDIATE SAID FIRST AND SECOND SELECTOR MEMBERS EFFECTIVE TO LIMIT RELATIVE ROTATION THEREBETWEEN TO AN AMOUNT LESS THAN TWO COMPLETE ROTATIONS AND TO CONNECT SAID SELECTOR MEMBERS FOR UNLIMITED SIMULTANEOUS ROTATION WITHIN TWO RELATIVE ROTATIONS; AND MEANS CONNECTED TO ONE OF SAID SELECTOR MEMBERS OPERABLE UPON MOVEMENT OF SAID ONE SELECTOR MEMBER TO A PRE-SELECTED POSITION WITH RESPECT TO SAID FIXED MEMBER, TO ENGAGE CORRESPONDING MEANS ON THE OTHER OF SAID SELECTOR MEMBERS TO PREVENT MOVEMENT OF SAID OTHER SELECTOR MEMBER TO CERTAIN OF ITS POSITIONS WITH RESPECT TO SAID ONE SELECTOR MEMBER. 